1. Field of the Invention
The present invention relates to a transmission control apparatus and an image forming apparatus with the transmission control apparatus.
2. Description of the Related Art
In general, as illustrated in FIG. 14, it is necessary for an image forming apparatus to have two cables. One is a serial communication cable such as a USB cable and used for serial communications between a first control unit and a second control unit in an operation panel. The other is a cable for an indication signal indicating a power supply mode from the first control unit.
However, in order to have two cables, it is necessary to have two sets of cable connectors and cables, which leads to increased cost and prevents from making smaller the apparatus.
Therefore, PLT 1 describes a technique in which it is possible for a plurality of control units/control boards to communicate with each other by using an asynchronous serial communication port capable of bidirectional serial communications and by allowing apparatuses to pulse-drive during the time widths predefined for the respective apparatuses.